Converting double array to struct array for generalized inverse kinematics

Hello,

    q0 = robot.homeConfiguration.JointPosition;
    numWaypoints = 5;
    qWaypoints = repmat(q0, numWaypoints, 1);

    gik = robotics.GeneralizedInverseKinematics;
    gik.RigidBodyTree = robot;
    gik.ConstraintInputs = {'position'};

    posTgt = robotics.PositionTarget(ee);
    posTgt.TargetPosition = [1 1 1];

    qWaypoints(1,:)= q0;
for k = 2:numWaypoints
    [qWaypoints(k,:),solutionInfo] = gik(qWaypoints(:,k-1), posTgt);

end

above is the code that I am working with. The error ouccurs at "gik(qWaypoints(:,k-1), posTgt)". So basically I need to convert the qWaypoints to struct array (currently it is an array of doubles). Is there an easy and simple way for this conversion ?

[Kevin Chng]

Hi,

I guess you have to

convert it to cell first

a=num2cell(gWaypoints);

later, use cell2struc() convert it to structure array.

I don't know how your qWaypoints array looks like, therefore i unable to help you to code it, however, you may refer to documentation :

https://www.mathworks.com/help/matlab/ref/cell2struct.html

[Walter Roberson]

Perhaps just set the robot DataFormat property to 'row'?

Answer 1

[Sebastian Castro]

Instead of converting back and forth, it's easier to stick to a consistent format -- either all structs or all numeric.

If you do either of the following,

robot.DataFormat = 'row';
robot.DataFormat = 'column';

then the robot configuration, including the solution of gik, will be a numeric row/column instead of a struct.

As an alternative, as you said, you can keep everything as a struct. You can simply your first line to

   q0 = robot.homeConfiguration

Then, repmat should handle the rest for initializing the array to be of structs rather than numeric.

Finally, your loop contents should become something like:

   [qWaypoints(k),solutionInfo] = gik(qWaypoints(k-1), posTgt);

- Sebastian